Supporting plate



FIG. 1 is a top plan view of our new, original and ornamental design for a supporting plate;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a bottom plan view thereof; and,

FIG. 4 is a right side elevational view thereof.

A rear elevational view is the same as the front elevational view of FIG. 2, and a left side elevational view is the same as the right side elevational view of FIG. 4. 

The ornamental design for a supporting plate, as shown. 